The concept for my book The Nolympicswas, from the publisher's point of view, a risky one – but it was theirs. It was to have me write up, daily, my experience, as a Londoner, of what it was like to follow the Olympics; moreover, as someone who was not looking forward to them one little bit. The idea, I suppose, was to have the comedy of frustration: in the old, Perelmanian sense of comedy being about getting a man up a tree, throwing rocks at him, and then, finally, getting him down from the tree. I was to be that man, and the Olympics were to be those rocks, and my cries of pain were to be the main substance of the book. "What if you end up enjoying them?" I was asked. "Not terribly likely," I replied. "If I do, then that will be part of the story." But the chief riskiness resided, as far as I could see, in the fact that it was me they had asked to do this. I am not known particularly for my industry; and, after all, I have yet to have a book published at all. And I was going to have to work quite hard indeed.

Writing a minimum of 1,500 publishable words a day, ideally 2,000, over a 17-day period is not a task that many writers would look to with enthusiasm. Then again, there are quite a few who would regard it as nothing special. On the one hand, you have Trollope knocking off 3,000 words a morning before setting off to work running the Post Office, and Gustave Flaubert writhing on the carpet in agony for hours as to where to place a comma. There is a certain amount of braggadocio involved when writers talk about this – especially male writers. There is no shame in saying you write slowly. The miracle, it is tacitly understood, is that any of it gets done at all; the speed you do it at isn't really that important, although if you say you write too many words a day, people start wondering if the quality control is strict enough, and if you say you write hardly anything, then people might ask themselves if you're being a bit precious, or how you can afford to feed yourself. For myself, about 1,500 words on the same subject is a day of Stakhanovite labour, to be rewarded by a big, self-administered pat on the back.

However, I know that, when pressed, and in the mood, and (I use the word in its loosest sense) inspired, I can write at great speed; it's one of the things that makes life as a hack a bit less difficult than it otherwise has to be. It is also a phenomenon along the lines of how it is sometimes better to run up three flights of stairs rather than walk up them: the body simply doesn't register that it's knackered, the lungs don't start telling you to slow down, until you're nearly at the end. It can be the slow, steady slog that kills and dispirits. And anyway, spread out over a working day, it's not that much: just as when you complain to the doctor that a bottle of wine a night is hardly anything if you're drinking only a glass an hour between six in the evening and midnight.

Still, it is alarming, like performing without a safety net, when you realise there is no time daily for anything but the most basic revision. The matter of tone, and its modulation or progress throughout the book, has to be settled on the hoof; a kind of honesty is forced upon the material, so if it seems as though the book starts flippantly but ends more thoughtfully, then that's because that's the way things were going on in my head.

By "thoughtful", again I mean tone. I do not mean in the careful avoidance of mistakes. Here are a couple towards the end which I will own up to, in order to spare the reviewers a bit of effort: for example, Humphrey Jennings's film was called London Can Take It, not Britain Can Take It; and whatever gremlin inspired me to give The Who's late bassist the first name "Robert" when I know perfectly well, and have done since I was 11, that it is "John", maybe one day the therapists will be able to nail it down and lay it to rest.

As for the Olympics themselves: although I did not go quite as hoopla about them as everyone else seemed to – or was induced to by peer pressure – I certainly found myself enjoying the whole spectacle much more than I thought I would. The athletes were gracious in victory, the volunteers wonderful. To clear the air of the toxins that had been building up before was quite something. I also discovered that I am really, really impressed by synchronised swimming.

In the end, though, I managed to produce 40,000 words over 17 days – all the while not neglecting my other jobs – which is, I suppose, something. (Also a couple of those days were spent travelling to and from Olympic venues and watching things.) There were times when the prospect of working sickened me: but I knew that any shortfall one day would mean it would have to be made up the next. Luckily, the whole phenomenon of the Olympics, and the country's reactions to it, was so interesting that there was never a shortage of material, and I like to think there isn't too much repetition within the book itself.

Themes, though, crop up: a recurring one, I discovered, is my fascinated loathing for Boris Johnson, a much more dangerous man than even his enemies seem to acknowledge, and if this book helps in any small way to put a brake on his political career, then I will at least be able to say I have achieved something.